Push-button electric switches



Oct. 30, 1956 w. BOURNE 2,769,050

PUSH-BUTTON ELECTRIC SWITCHES Filed April 25, 1955 2 Sheet's Sheet l W. G. BOURNE PUSH-BUTTON ELECTRIC SWITCHES Oct. 30, 1956 2 Sheets-Sheet 2 Filed April 25, 1955 3 Fig.2

I12 verb-ta A. G .EO'LLZDZZA? United States Patent PUSH-BUTTON ELECTRIC SWITCHES William George Bourne, Gunnersbury Park, Acton, London, England, assignor to Rotax Limited, London, England Application April 25, 1955, Serial No. 503,559 Claims priority, application Great Britain May 4, 1954 1 Claim. (Cl. 200-67) This invention has for its object to provide in a convenient form, a push-button electric switch for effecting temporary closing of one of a pair of associated electric circuits, the other circuit being normally closed by the switch.

A switch in accordance with the invention comprises a centrally pivoted contact bar adapted at its end to cooperate with a pair of fixed contact pieces, a pair of interconnected and relatively movable pivoted members, and a spring-loaded push button acting on one of the said members, the other member serving to actuate the contact bar, and the arrangement being such that depression of the push button serves to close the circuit connected to one of the fixed contact pieces, this circuit being re-opened on release of the push button.

In the accompanying drawings, Figures 1 and 2 are respectively a sectional front elevation and sectional side elevation of a switch embodying the invention.

Referring to the drawings, a hollow body part a contains a separately formed base b on which are secured a pair of fixed contact pieces 0, these being connected to circuit terminals beneath the base and being situated at opposite sides of the centre of the base. To the underside of the upper end of the body part is secured by screws d a sheet metal bracket e comprising a pair of similar side cheeks arranged parallel with each other, the base b being secured to the lower end of the bracket by a bush 1 to which is attached a terminal g. Between the said cheeks and at the end of the bracket adjacent to the base is provided a transverse pivot pin h on which is centrally supported a contact bar 1 having a contact piece j at each end for co-operating with the fixed contact pieces c, the latter being connected to terminals k.

In the upper end of the body part is mounted a hollow and axially movable push button m which contains a spring 11. Preferably the push button is made from electrically insulating material and is provided with a metal tubular lining 0 and to the inner end of the lining is secured a transverse pin p which at its ends enters slots q in the cheeks of the bracket, which slots are such as will permit the required range of movement of the push button.

Within the bracket is pivoted a lever-like member r made by folding a metal sheet to form a pair of similar side parts situated at a sufficient distance apart to accommodate a second lever-like member s. The member r is pivoted on a pin t which passes through slots u in this 2,769,050 Patented Oct. 30, 1956 ICC member and is secured at its ends to the bracket, the pin being located at a distance from one side of the axis of the push button. The pin p above mentioned on the push button passes through holes in the member r, so that movement of the push button can impart angular movement to the said member about the pin t. The member s is shaped at one end to bear against an abutment piece v which bears against the free end of the spring 11. Also in this member is formed an arcuate slot w through which passes the pin 2 on the push button. Further the inner end of the member s has secured to it a pin x, carrying a pair of coaxial rollers y which ride on the contact bar i, and this pin also passes through slots z in the side parts of the member r.

In the example illustrated the lower end of the switch body part has attached to it by screws 2 a removable cover piece 3 which encloses the terminals, g, k. The arrangement is such that the contact bar i normally occupies a tilted position as shown in Figure l in which one of its contact pieces rests on the associated fixed contact piece, the bar being held in this position by the pressure of the spring n acting through the pivoted member s and the rollers y on the said member. To effect temporary opening of the normally closed circuit and closing of the other circuit, the push button is depressed. This causes the pivoted member r to be moved about its pivot axis at and transmit a movement to the member s thereby causing the rollers to ride from one side of the pivot axis to the other of the contact bar i and so close together the contact pieces controlling the other circuit. On releasing the push button the spring u restores the parts to their normal positions.

Having thus described my invention What I claim as new and desire to secure by Letters Patent is:

A push-button electric switch comprising in combination a pair of fixed contact pieces, a centrally pivoted contact bar adapted at its ends to co-operate respectively with said contact pieces, a first pivoted member arranged to act on said contact bar, a push-button, a second pivoted member operatively connected to said push-button, a loading spring arranged between and acting on said pushbutton and first pivoted member, and normally serving the dual purpose of retaining said push-button in its initial position and causing said first pivoted member to retain said contact bar in a position in which it co-operates with one of said contact pieces, and means interconnecting said first and second pivoted members so that movement of said second pivoted member in response to depression of said push-button is accompanied by relative movement of said first pivoted member for moving said contact bar into another position in which it cooperates with the other of said contact pieces until said push-button is released, whereupon said first and second pivoted members and said contact bar return to their initial positions under the action of said spring.

References Cited in the file of this patent UNITED STATES PATENTS 2,047,950 Douglas July 21, 1936 

